The generation of perspiration by the human body is a well known bodily function which is due mainly to climatic changes and physical exertion. In this manner the body provides a natural cooling system. Although the degree of perspiration generated varies from person to person, under certain circumstances the human body will always perspire. However, whilst perspiration is a natural bodily function, it is also often associated with a lack of bodily hygiene and cleanliness. In addition, the majority of people also experience discomfort whilst perspiring.
In addition, perspiration is typically also associated with the staining of clothing, which is unsightly. This problem is exacerbated by certain types of design of clothing such as tight fitting clothing and the use of synthetic materials in clothing manufacture. Unfortunately, this type of perspiration related staining of clothing is difficult to remove and often remains visible on clothing after washing or dry cleaning.
Furthermore, another problem related to the generation of perspiration is the associated and distinctive unpleasant odour. Malodorous compounds typically present, may originate from a number of sources. Firstly, the actual components of the fluid discharge i.e., perspiration may contain malodorous compounds. Secondly, malodorous compounds are also generated as a result of the degradation of the components of perspiration.
The presence and particularly the detection of perspiration is the cause of considerable embarrassment to many people, especially those people suffering from a tendency to perspire heavily. Hence, it is highly desirable to prevent the detection of human perspiration.
One means of addressing this problem is the use of antiperspirants or deodorisers which are applied to the skin in the form of aerosols, roll-ons, sticks and gels. For example EPO 710 812 discloses a method of preventing underarm malodour associated with human perspiration by the use of a macroporous crosslinked copolymer containing acrylate or methacrylate units. The polymer entraps the fatty acid components of perspiration and thereby denies access to the acid by skin bacteria and consequently reduces body malodour.
However, for many people antiperspirants and deodorants are not particularly effective. Furthermore, there is a desire of many consumers to avoid the use of such compounds on the skin as many of these compounds are considered as skin irritants and also as it is not considered to thereby hinder the body's natural reaction to perspire. In addition, such products also do not address the problem of staining of clothing. In fact, many antiperspirant products cause additional staining of clothing and contribute to the degradation of the clothing itself.
An alternative means of addressing the problem of the generation of perspiration is to use absorbent articles. Such articles have been long recognized as a means of addressing this problem and there are a number of reference to articles designed specifically to absorb perspiration, particularly designed for utilisation on areas of the body susceptible to perspiration such as the armpit, neck or soles of the feet. For example the perspiration pads as described in U.S. Pat. No. 467,898, DE 31 04 047, DE 28 41 365 and DE 39 09 218.
The primary focus of such perspiration pads is to absorb and retain fluids. This is typically achieved by providing a pad having an absorbent material and a liquid impervious backing material. In this manner the pad absorbs the excreted fluids, prevents the staining of clothing and provides wearer comfort by improving the dryness of the surface of the skin, where perspiration occurs. Another important area of development in this field is also the control of odorous compounds contained within the pads during their use.
There are numerous disclosures in the art, particularly in the field of sanitary napkins, which describe various compounds which provide odour control for use in absorbent articles. These odour control agents typically function by physical absorption of the odorous compound or by chemical interaction with the odorous compounds or their precursors or by masking the odour for example by the use of perfumes.
The use of odour control agents specifically in perspiration pads has also been in the art. For example EPO 333 773 discloses an antiperspirant pad with an absorbent layer, a thin water impervious layer having an attachment means for attachment to garments, wherein the absorbent layer contains microencapsulated actives.
Also DE 33 39 474 discloses anti-perspiration underarm pads having attachments means to garments which are also easily removed from garments comprising an absorbent material and a perfume carrier or active which terminates bacteria or microbes and is preferably encapsulated.
DE 26 17 545 discloses underarm perspiration pads comprising a coverlayer and a lower layer, the lower layer having garment attachment means. In addition the pad may contain antibacterial agents or perfume.
However, the above described odour control agents all have associated drawbacks. Many odour control agents do not provide effective odour control over a range of odours and are not effective against odours generated from perspiration.
Disposable garment shield for prevention of garment soiling and combating perspiration related odours has been disclosed in U.S. Pat. No. 5,103,500. The shield comprises a laminated body having a layer of non absorbent polymer which has adhesive attaching material, a moisture absorbing layer and a dry deodorant mixture activated by perspiration.
However, there still exists a need to provide alternative odour controlling agents or systems for effective utilization in perspiration pads. In particular, there exists a need to provide an odour control agent or system for the prevention of the detection of malodorous compounds within pads by addressing the source of the formation of the odour.
It has now been surprisingly found that the combination of a perspiration pad having a breathable backsheet together with an odour control system provides an unexpected improvement in the odour control performance of the odour control system.
The incorporation of breathable backsheets in absorbent articles such as sanitary napkins for improved wearer comfort has been described in the art such as for example in GB 2 184 389, U.S. Pat. No. 3,881,489 and EPO 203 821. U.S. Pat. No. 4,059,114 discloses the incorporation of antimicrobial agents in sanitary napkins which have vapour permeable backsheets. However, none of these prior art documents recognise the benefits of the combination of a breathable backsheet with an odour control system in perspiration pads.
It is believed that the synergic odour control performance benefit of a breathable perspiration pad in combination with an odour control agent is due to a number of factors.
Firstly, the breathability of the pad results in increased movement of the volatile malodorous compounds. Hence, the amount of actual physical contact between these compounds and the odour control agents increases. Contact between the odour control agents and the malodorous compounds is usually required in order to effectively combat the odorous compound. Frequently, large quantities of the odour control system is required within the perspiration pad order to ensure its effectiveness. This is because the odour control agents do not necessarily contact all the malodorous compounds present. Hence the cost of these products increases, so it is desirable to avoid the necessity of large quantities of the odour control system. In the present invention, the effectiveness of the odour control agent is significantly increased and thus the full capacity of the odour control agent can be utilised and hence less may be required.
Secondly, the breathability of the absorbent pad reduces the hot humid and anaerobic environment between the skin of the wearer and the surface of the perspiration pad. This hinders the growth of microorganisms, which are also known to be responsible for the generation of odorous compounds. Thus, the amount of odours associated with the presence of microorganisms is reduced by the perspiration pads of the present invention.
Thirdly, the reduction in the hot, humid and occlusive environment between the vicinity of the skin of the wearer and the wearer facing surface of the perspiration pad itself also reduces the tendency of the wearer of the product to perspire. Consequently, the amount of associated perspiration related odour will be reduced. Thus, the breathability of the pad actually reduces the amount of odour generated within the perspiration pad. As a result the odour control system works more effectively on the remaining odorous compounds present in the article.
In addition, due to the breathable nature of the pad, the malodorous compounds contained therein may, similar to water vapour and air, be more readily exchanged with the environment. Hence, malodorous compounds are able to escape from the article and are dissipated into the surroundings. More importantly, the breathability of the pad also allows the precursors compounds of malodorous compounds present in the article to escape from the perspiration pad before degradation commences and hence before malodour formation takes place.
A further advantage of the perspiration pads of the present invention is that the need to use antiperspiration products is eliminated thereby allowing the body to perspire naturally without the possibility of the generation of stains on clothing or detection of malodours.